Making tofu may sound complicated but if you have all the necessary tools and ingredients it is really quite simple as long as you follow the recipe.
I am making Chinese tofu with calcium sulphate or more commonly known as gypsum or plaster of paris. Please do not buy this ingredient from the DIY shop or plaster used for broken arm, you need to get a food grade one from most of the larger Chinese supermarkets. If you can’t find in Chinese supermarket you can buy online from here
Japanese tofu is made with magnesium chloride or Nigari which is an extract from sea water. Nigari is not as widely available as calcium sulphate in England. I have only seen some on Ebay or 5 kg pack from an online shop. Not used Nigari before so I don’t really know what quantity is required.
You can also make tofu with lemon juice but this will give a distinctive sour taste.
See this slideshow for the know how.
For the ingredients you only need soya beans, calcium sulphate and plenty of water.
750 g of soya beans + water for soaking
5 - 5.25 litres of water for juice extraction
5 tsp or about 15g of calcium sulphate + 250 ml of warm water
To ground and extract the juice you need a liquidiser and a bag made with muslin about 30 cm x 22- 25cm, do make the bag with double layers to ensure it is strong and lasting.
For the press, you need:
- a wooden or metal mould, preferably square or rectangular with a lid or in the case of a square cake tin a loose bottom which you can use the loose plate on top. If you don’t want to buy a mould you can use a normal large round spring form cake tin (spring loosen), use the loose bottom on the top same as the tofu mould lid. The size of the mould I am using is 21 x 21 x 8 cm (inside measurement)
- Next is square piece of muslin, measure about 3 times the width of the mould or tin.
- Then you need some heavy object to press the curd, I use few clean bricks wrapped in foil to keep them clean and tidy.
- A rack and a mesh like a pizza screen to help the liquid run into the sink during pressing.
Other tools required are:
- one large stock pot enough to hold all the liquid. For this recipe I use a 5 litres pot.
- One large plastic container or another stock pot to holding the liquid/bean mixture during juice extraction.
- Couple of ladles, a jam thermometer, couple of clothe pegs, a water jug and a measuring jug, a fine sieve
- Soak the beans for 6 – 8 hours. Clean and drain.
- put the beans in batches into a liquidiser with water (fill the liquidiser with 1/3 full beans then fill up to ¾ full with water). Blend for about 1 minute till you get a white frothy quite smooth slush. Put this into a large container, continue blending till you have used up all the beans. Any water left from the measured 5 litres of water pour into the bean slush and mix.
- Put a stock pot in the sink and the large bowl of pulverised bean slush on top of the draining board. Take the muslin bag, peg it to the side of the bowl so you have enough room to pour the slush into the bag. Half filled and twist the top of the bag and squeeze till all the juice is released. You will get about 5 litres full of milk with plenty of froth on top. Remove the pulp from the bag, clean it really well without any grains left. Clean the empty container too. Do a second filtering to ensure there is no grains of bean pulp in the milk which will affects the texture of the tofu and any grains of beans will stick to the bottom of the pot during boiling and cause the pan to stick and burn. When you do the second filtering, fill as much as you like, when nearly full give the bag a gentle squeeze and you will filter the milk in less than 2 minute. Clean the bag and empty pot. You will find quite a lot of froth on the milk, don’t worry they will disappear once heated.
- You will get a pile of semi wet bean pulp after extraction. I normally chuck the bean pulp but if you like you can cook it and make bean burgers, vegetarian mince or feed that to the bird etc…
- Boil the milk at medium heat till about 95 deg C or when you see small boiling bubbles coming up, turn the heat to low and continue heating and stirring for another 10 minutes. While you are boiling the milk, do not leave the kitchen, if the milk boil over it will make a bloody mess and you will end up with only ½ pot of milk. You need to stir right from the beginning during boiling about every minute to ensure the milk does not stick to the bottom of the pot. Cover the milk and let it rest for 10 – 15 minutes, while you check the temperature not going down to less than 90 deg C. Do make sure you cover the milk or you will get skin on top. Get a fine sieve and dip into the milk to fish out any impurities and also any bubble on the top of the milk. Any impurities will affect the smoothness of the tofu.
- Continues checking the temperature of the milk, once it has got to about 85 – 88 deg C. Time for action. Stir the calcium sulphate with the warm water vigorously second before you pour into the milk. Have a ladle in the milk, pour the coagulant in from a height, stir the milk at the same time very vigorously with the ladle for 2 – 3 seconds only. Then cover and leave it alone. The milk will completely its cudling in about 10 minutes. Leave to cool for about 30 - 40 minutes.
- Wash the mould, put it on a rack with or withour a metal mesh on top of the sink drainer. Wet the muslin liner, carefully line it inside the mould to fill all corner. Scoop the curd into the mould and fill it right to the top. Cover with muslin. Put the top on, then add the weight which is 2 – 3 pieces of brick.
- Let the curd press and drain till the volume has reduced to half, this will take about 30 minutes – 2 hours depending on the pressing weight. Volume reduced about half will give a silken texture, remove the mould cover and the muslin, test it with your finger when you touch the tofu it should be quite firm but not very hard in the centre, if it is wobbly its too soft, and you need to press for a bit longer. If you like a very firm tofu leave it to press for longer. The above picture showed the result which I was quite please having not practised for years. The recipe makes 9 square pieces, measure 7 x 7 x about 4 cm.
- This tofu should be kept in the fridge, fill the container with water. Change the water everyday if you can remember and this will help to keep it for longer. Will keep for about 1 week to 10 days maximum. If the tofu feels slimy or smells sour it is off.